1. Field of the Invention
The present invention relates to an external combustion engine using the change of volume of a working fluid accompanying generation and liquefaction of steam of the working fluid to cause displacement of a liquid part of the working fluid and converting this to mechanical energy for output.
2. Description of the Related Art
In the past, this type of external combustion engine was described in Japanese Unexamined Patent Publication No. 2007-255259. In this prior art, the average pressure of the internal pressure of the main container was made to approach a target pressure for the purpose of improving the output and efficiency of the external combustion engine.
Explaining this in brief, liquid is sealed in an auxiliary container separate from the main container in which the working fluid is sealed, this auxiliary container and main container are communicated through a venturi means, and the liquid in the auxiliary container is heated by an auxiliary heater to vaporize it.
The auxiliary container and the auxiliary heater are configured so that the internal pressure of the auxiliary container becomes close to the target pressure. Due to this, the average pressure of the internal pressure of the main container is made to change tracking the internal pressure of the auxiliary container and the average pressure of the internal pressure of the main container is made to approach the target pressure.
According to this prior art, it is possible to maintain the average pressure of the internal pressure of the main container at substantially the target pressure without using a control device or various types of sensors etc., so the output and efficiency of the external combustion engine can be improved by a simplified configuration.